Diastolic function Flashcards
Test 2
What are the 4 phases of diastole
- Isovolumic relaxation (IVRT)
- Early rapid diastolic filling
- Diastasis
- Late diastolic filling due to atrial contraction
The time from the closure of the mitral valve to the opening of the aortic valve
IVCT
Sequence of events during IVRT
- Closure of AoV
- LV pressure falls rapidly
- LV pressure falls below LA pressure
- Mitral valve opens
During IVRT what is happening to the LV pressure and its volume
LV pressure is decreasing
Volume remains unchanged
Isovolumic Relaxation Time (IVRT)
Time between AoV closure and the MV opening
Diastasis results because
pressure difference in LA and LV equalize
Early rapid diastolic filling
blood flows from LA to LV
Late diastolic filling, atrial contraction results in:
- LA pressure exceeds LV pressure
- MV opens
- Second pulse of LV filling occurs
- This is responsible for only about 20% of ventricular filling
Diastole for RV
- Similar to LV
- Reciprocal respiratory variation w/RV filling
- Lower velocities
- Total duration of diastole is shorter
RV inflow view
Apical four-chamber view
RV inflow
Parameters of diastolic function
- Ventricular relaxation
- Myocardial compliance
- Chamber compliance
Definition of compliance
The measure of a hollow organ to resist recoil towards its original dimensions upon removal of a distending or compressing force
(Ventricle stretches and relaxes)
Ventricular relaxation occurs during
isovolumic relaxation and early diastolic filling
- is an active process (myocardium uses energy)
What are factors that affect LV relaxation
- Load
- Inactivation of myocardial contraction
- Asynchrony
Results of abnormal relaxation
- Prolongs IVRT
- Ventricular pressure has slower rate of decline
- Reduction in early peak filling rate
- Pressure difference between LA and LV is not as great when AV valve opens
LV relaxation time can be measured using:
- IVRT
- Maximum rate of pressure decline (-dP/dT)
Compliance
Ratio of change in volume to change in pressure (dV/Dp)
Stiffness
Ratio of change in pressure to change in volume (dP/dV)
What factors affect chamber compliance/stiffness
LV geometry
- Ventricular size
- Ventricular shape
Characteristics of myocardium
- Myocardial stiffness
Extrinsic factors outside LV
- Pericardium
- RV interactions with LV
- Pleural pressure
What parameters can be evaluated invasively
- TAU (time constant - relation between LV pressure and time)
- IVRT
- End diastolic pressure
- Compliance of LV chamber stiffness using dP/dT
What are 2D/M-mode indicators of diastolic dysfunction
- Could be present w/systolic dysfunction
- Motion of the posterior wall on m-mode
- Pericardial thickening
- Septal motion w/respiration
- Dilated IVC and hepatic veins
- Tissue characterization of myocardium
- LA max volume index is the most useful 2D measurement method
LA remodeling can happen from
- Diastolic dysfunction
- Tachycardia
- ischemia
- Valve disease (MS or AS)
LA pressure increases to maintain adequate LV filling, this is associated with
increase LV stiffness and decrease LV compliance
How does diastolic dysfunction affect the LA size
- Increases filling pressure and causes LAE
- Severity of diastolic function correlates well w/LA volume
- Longstanding effects of LA dilation is a decrease in LA function
LA enlargement can also be form:
- Volume overload from MR
- Arteriovenous fistula
- High output states like anemia
- Athletes heart w/no cardiovascular disease
- Bradycardia
- 4 chamber enlargement
- A-fib or flutter
Why are volume measurements preferred over linear measurements
due to asymmetric remodeling of the chamber
What are the two methods to assess LA volumes
- Biplane area-length method
- Simpsons biplane method
Normal LA volume is indexed by dividing it by?
BSA
What are the echo Doppler parameters of diastolic function?
- Peak E and A velocity of MV
- MV A wave duration
- MV E/A ratio
- MV DT
- TDI e’ velocity
- Mitral e/e’
- P vein S,D and A wave velocity
- P vein A wave duration
- P vein S/D ratio
- CW TR peak velocity
- Color propagation m-mode
- Valsalva
- Secondary measurements:
- Color m-mode propagation
- TE-e’
What wave correlates to early rapid diastolic filling
E wave
What wave correlates to late diastolic filling due to atrial contraction
A wave
Normal IVRT
≤ 70 msec
Myocardial compliance
characteristics of isolated myocardium
Chamber compliance
charactersitics of the entire chamber
LA volume is ultimately a good predictor of outcomes in a number of different conditions:
- hypertensive heart disease
- A-fib
- cardioversion success
- dilated cardiomyopathy
- hypertrophic cardiomyopathy
- ischemic stroke
- coronary events
LA volumes reflect the ____
unlike Doppler measurements which reflect ____
- cumulative effects of filling pressure over time
- changes at that moment in time
Abnormal LA volume
> 34 mL/m^2
What is measured on the mitral inflow
- E wave
- A wave
- E/A ratio
- DT
- Duration of A wave
- IVRT
Factors influencing E wave
- changes in pressure difference between ventricle and atrium (opening pressure) caused by changes in preload
- changes in transmitral volume flow rate
- change in atrial pressure
- decreases with age
Increased preload results in:
- Increased E velocity
- Shortened IVRT (due to the quick increase in LA pressure
- Steeper deceleration slope in early diastolic filling
- Small A velocity (LV pressure is higher so gradient between LA and LV is not as high)
Reduced preload results in:
- Reduced E velocity (chamber gradient is decreased)
- Does not affect atrial contraction
- Hypovolemia or venodilator can cause decreased E velocity
Factors affecting late diastolic filling (A wave)
- Cardiac rhythm
- Atrial contractile function
- Ventricular end-diastolic pressure
- HR
- Timing of atrial contraction (PR interval)
- Ventricular diastolic function
- Increases with age
L wave
Happens when there is markedly delayed LV relaxation in the setting of elevated LV filling pressures that allows ongoing LV filling in mid diastole
PT usually have bradycardia
The valsalva maneuver decreases
Preload and LA pressure
With valsalva where should you see a decrease at maximal strain
E and A wave velocity
What does valsalva help determine
- if pts are in pseudonormalized pattern
- if there is a significant increase in LV filling pressures
During valsalva what indicates an increased LV filling pressure
Decrease of the E/A ratio of ≥ 50% or an increase of the A velocity
TDI Doppler is recording
the velocity of movement of myocardium (wall motion) instead of intracavity blood flow velocities
TDI septum
- more reproducible because it is parallel
- RV influence
TDI Lateral
- RV influence
- not as parallel to flow
Normal ratio of e’/a’ prime (TDI)
> 1.0
What correlates to the S wave in the pulmonary vein during atrial diastole and ventricular systole
Systolic predominance or antegrade flow
What creates the D wave (or diastolic veloctiy) within the pulmonary veins
Early diastolic filling following opening of the MV generates the MV inflow which creates the D wave
What creates the A wave of the pulmonary vein
In late diastole, atrial contraction generates the mitral inflow A wave and the plum vein retrograde flow (A wave of P vein)
Which pulmonary vein wave is most predominant in pts younger than 40
Diastolic (D) wave
Elevated ventricular diastolic pressures (LV-EDP) are also reflected in
elevated atrial pressure
Normal LA pressure
5-10 mmHg
Increasing LA pressure leads to increased
reliance on atrial contraction to empty the LA
This shows up as increased D wave velocity
Lt heart respiratory variation compared to Rt heart
- Lt is less prominent
- Lt is directionally opposite
- Diminishes during inspiration as blood “pools” in pulm veins not because of negative intrathoracic pressure
Conditions that influence systolic atrial filling
- Age
- LA size
- Changes in LA pressure
- Atrial contractile function
- LV and RV contractility
Conditions that influence diastolic atrial filling
- Gradient from pulm. veins to LV
- LV filling and compliance
- Changes in parallel w/mitral E velocity
Noninvasive estimates of LV end diastolic pressure
LA pressure is equivalent to LVEDP
Can use AI jet to calculate
AI calculations of LVEDP limitations
- Need to have recordable AI jet
- Must have accurate cuff diastolic measurement
- Small errors in either value can result in much larger errors in final value
Normal RA pressures
0-5 mmHg
RA filling characteristics
- Small reversal of flow following atrial contraction (a wave)
- Systolic phase (IVC and SVC fill atrium)
- Small reversal of flow at end-systole (v-wave)
- Diastolic filling phase (RA serves as a channel between the systemic venous return and the RV)
Jugular Venous Pulsation (resembles hepatic vein doppler)
- A wave: follows atrial contraction
- X-descent: corresponds to artial systolic filling
- V wave: corresponds to ventricular contraction
- Y-descent: corresponds to atrial diastolic filling
A disease process should affect JVP and RA filling Doppler patterns in the ____ manner
same
Which two veins empty directly into the RA w/o interference from venous valves
- SVC (suprasternal notch)
- Central hepatic vein (subcostal view)
RA filling changes with respiration: Inspiration
- Pressure gradient from extrathoracic to intrathoracic ___ so great veins ____ flow to RA
Increase
Increase
RA filling changes: IVC size
- Dilated IVC ____ RA pressure
- Reduced IVC ____ RA pressure
- Increases
- Decreases
Abnormal IVC measurement
> 2.1 cm
Normal IVC collapsibility
> 50%
Abnormal < 50%
Other findings that may justify normal or abnormal RAP
- Dilated RA
- Interatrial septum that bulges into the LA throughout the cardiac cycle
Other causes of dilated IVC
- Athletes
- Pts on ventilators
Color flow
- Normal flow:
- LV systolic dysfunction:
- Prosthetic MV valves:
- Along posterior lateral wall
- Lower velocity “puffs” of inflow
- Flow directed along anteromedial wall
Color Doppler m-mode records ___ and measures ___
- Records LV inflow from apical view
- Measures the propogation velocity as blood goes from annulus to apex
Flow propogation velocity (Vp) is defined as
the slope of the first aliasing velocity during early LV filling
Flow propogation velocity (Vp) is normal when
0.5 m/sec or greater
This is decreased w/restrictive ventricular filling (or decreased relaxation) and increased w/ constrictive pericarditis
Color m-mode Doppler steeper the slope the
better the Vp
Myocardial performance (TEI index)
- Based on Doppler derived time intervals
- Combines systolic and diastolic cardaic performance
- Use PW Doppler or DTI
- Higher index values correlate w/pathologic states of overall dysfunction
Normal value of LV TEI index is
0.39 (+-) 0.05
TEI advantages:
- Noninvasive
- Easy to obtain
- Reproducible
- Independent of arterial pressure, HR, AV valve regurg, ventricular geometry, afterload and preload in supine pts
TE-e’ measurement is obtained by
- Getting a MV inflow waveform at the leaflit tips and getting a septal and lateral TDI velocity
- ## Measure interval between peak R wave in QRS and onset of MV E velocity and subtract from time interval between QRS complex and onset of e’ velocity
TE-e’ measurement can identify pts w/dyastolic dysfunction
due to delayed onset of e’ velocity compared with onset of mitral E velocity
Impaired LV relaxation results in:
- rapid early diastolic filling
- short IVRT
- rapid acceleration time
- high E velocity
- steep deceleration time
- atrial contribution is small
- plum vein shows D wave > S wave and a prominent A wave
Abnormal LV compliance causes:
- Rapid early diastolic filling following MV opening
- Short IVRT
- Rapid acceleration time
- High E velocity
- Steep deceleration slope (which leads to decrease deceleration time)
- Atrial contribution is small (not much of gradient)
- Pulm veins show D wave > S wave and a prominent A wave
Despite impaired LV relaxation, markedly elevated LA pressure causes:
- High velocity of early diastolic filling
- Stops abruptly because of abnormally rapis rise in ventricular pressure and atrical dysfunction
Diastolic stress testing is most appropriate in patients with
dyspnea and grade I dysfunction at rest
Diastolic stress testing is considered positive when all of the following three conditions are met during exercise:
- Average E/e’ > 14 or septal E/e’ ratio > 15
- Peak TR velocity > 2.8 m/sec
- Septal e’ velocity < 7 cm/sec
Causes of diastolic dysfunction:
- Hypertension
- CAD
- LV fillinig patterns post acute MI
- Diabetic cardiomyopathy
- Obesity
- Hypertrophic cardiomyopathy
- Restrictive Cardiomyopathy (RCM)
- Amyloidosis
- Hemosiderosis
- Cardiac sarcoidosis
- Hypereosinophilic syndrome
- Systemic sclerosis
- Pericardial disease
2 principle mechanisms are responsible for diastolic dysfunction:
- Impaired active ventricular relaxation
- Incresed passice myocardial stiffness (decreased compliance)
Disease catergories that cause diastolic dysfunction:
- Secondary to LV hypertrophy and HTN
- CAD
- Primary myocardial disease (DCM, hypertrophic cardiomyopathy, restrictive cardiomyopathy)
- Extrinsic constraint (pericardial tamponade or pericardial constriction)
What is the most common reason for development of diastolic dysfuntion
HTN
Diastolic dysfunction is present in hypertensive pts far in advance of
HF symptoms
Chronic pressure overload casues:
- Cardiomyocyte hypertrophy
- Enhanced collagen deposition
- Reduction of microvascular density
- LVH
- Increased stiffness in systole and diastole
- Impaired relaxation
- Kidney is also affected and renal dysfunction worsens HTN
What are examples of mechanisms leading to diastolic dysfunction secondary to LV hypertrophy:
- HTN
- AS
- Congenital heart disease
Ishcemia usually results in ____ dysfunction before ____ dysfunction is seen
Provided pt has not had prior MI
- Diastolic
- Systolic
Large MI and significant systolic dysfunction results in
pseudonormalized pattern from reduced compliance and high LVEDP
Diabetic cardiomyopathy (DM) defined as
abnormal myocardial function in the absence of HTN, valvular disease, or coronary heart disease
Cardiac remodeling in diabetic cardiomyopathy (DM) progresses through 3 stages:
- Early asymptomatic
- Middle stage
- Lat stage
Early stage of DM
- Myocardial damage at molecular level
- Can manifest as LVH w/abnormal diastolic function
- Changes are subtle to strain imaging, strain rate and tissue velocity are needed for evaluation
Middle stage of DM
- Cardiomyocyte hypertrophy and fibrosis progress
- Diastolic function worsens
- Conventional echo techniques can detect
Late stage or DM accompanied by:
- Over HF
- Micro and macrovascular CAD
- HTN adn cardiac autonomic neuropathy
Is obesity more common in pts with diastolic dysfunction or systolic dysfunction?
diastolic dysfunction
Diastolic dysfunction is prevelant w/HCm due to:
- Increased afterload
- Myocardial fibrosis
- Myocardial hypertrophy
What is the most common restrictive cardiomyopathy (RCM)
Amyloidosis
Hemosiderosis
Iron overload
- can present as either restrictive diastolic dysfunction or a DCM
What is an autoimmune disease that can cause severe dysfunction of any organ, including vasculature
Systemic sclerosis
- hallmark: estensive fibrosis
- often has associated HTN
What is measured on diastolic dysfunction grades chart?
- LV relaxation
- LA pressure
- Mitral E/A ratio
- Average E/e’ ratio
- Peak TR velocity (m/s)
- LA volume index
Normal TDI measurments
- Septal
- Lateral
- Averaged E/e’ ratio
- > 7cm
- > 10 cm
- < 14
E/e’ not as reliable in patients with:
- MAC
- MS
- Mitral prosthesis
- Constrictive pericarditis